Dr. Ranganath R. Navalgund Profile

Dr. Ranganath R. Navalgund

Vikram Sarabhai Distinguished Professor at Indian Space Research Organization

SPIE Involvement:

Author

Proceedings Article | 7 May 2016 Paper

Optimization of spectral bands for ocean colour remote sensing of aquatic environments

P. V. Nagamani, Aneesh Lotliker, R. Navalgund, V. Dadhwal, K. Rao, T. Srinivasa Kumar, T. Preethi Latha

Proceedings Volume 9878, 987808 (2016) https://doi.org/10.1117/12.2225870

KEYWORDS: Sensors, Remote sensing, Signal to noise ratio, Atmospheric corrections, Remote sensing, Absorption, Luminescence, Near infrared, Aerosols, Short wave infrared radiation, MODIS

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Selection of central wavelengths, bandwidths and the number of spectral bands of any sensor to be flown on a remote sensing satellite is important to ensure discriminability of targets and adequate signal-to-noise ratio for the retrieval of parameters. In recent years, a large number of spectral measurements over a wide variety of water types in the Arabian Sea and the Bay of Bengal have been carried out through various ship cruises. It was felt pertinent to use this precious data set to arrive at meaningful selection of spectral bands and their bandwidths of the ocean colour sensor to be flown on the forthcoming Oceansat-3 of ISRO. According to IOOCG reports and studies by Lee and Carder (2002) it is better for a sensor to have ~15 bands in the 400-800 nm range for adequate derivation of major properties (phytoplankton biomass, colored dissolved organic matter, suspended sediments, and bottom properties) in both oceanic and coastal environments from observation of water color.

In this study, ~417 hyper-spectral remote-sensing reflectance spectra (spectral range varies from ~380-800 nm) covering different water types like open, coastal, mid coastal and near coastal waters have been used to identify the suitable spectral bands for OCM-3. Central wavelengths were identified based on the results obtained from hyper-spectral underwater radiometer measurements of Rrs, HPLC pigments and spectrometer analyzed absorption spectra for all the above water types. Derivative analysis has been carried out from 1st to 5th order to identify the inflection and null points for better discrimination / identification of spectral peaks from the in situ R_rs spectra. The results showed that open ocean and coastal ocean waters has spectra peaks mostly in the blue, green region; turbid coastal waters has maximum spectral peaks in the red region. Apart from this, the spectral peaks were identified in the red region for the chlorophyll fluorescence in the open ocean and coastal waters. Based on these results 13 spectral bands were proposed in the VNIR region for the upcoming OCM-3 sensor. In order to obtain water leaving radiances from the measurements at spacecraft platform, it is necessary to do atmospheric correction we need to have spectral bands in the NIR and above regions. Hence, a set of bands 3 bands in the NIR and SWIR region were proposed for OCM-3 to address the atmospheric correction related issues.

Proceedings Article | 22 December 2006 Paper

On-orbit spatial resolution estimation of IRS—CARTOSAT-1 cameras with images of artificial and man-made targets: preliminary results

A. Senthil Kumar, A. Manjunath, K. Rao, A. S. Kiran Kumar, R. Navalgund, K. Radhakrishnan

Proceedings Volume 6405, 64050W (2006) https://doi.org/10.1117/12.697001

KEYWORDS: Modulation transfer functions, Cameras, Satellites, Point spread functions, Spatial resolution, Satellite imaging, Infrared cameras, Signal to noise ratio, Sensors, Infrared imaging

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Proceedings Article | 7 December 2006 Paper

How far SAR has fulfilled its expectation for soil moisture retrieval

Hari Shanker Srivastava, Parul Patel, Ranganath Navalgund

Proceedings Volume 6410, 641001 (2006) https://doi.org/10.1117/12.693946

KEYWORDS: Soil science, Synthetic aperture radar, Surface roughness, Backscatter, Polarization, Data modeling, Agriculture, Dielectrics, Vegetation, L band

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Proceedings Article | 7 December 2006 Paper

Estimating wheat yield: an approach for estimating number of grains using cross-polarised ENVISAT-1 ASAR data

Parul Patel, Hari Shanker Srivastava, Ranganath Navalgund

Proceedings Volume 6410, 641009 (2006) https://doi.org/10.1117/12.693930

KEYWORDS: Synthetic aperture radar, Head, Backscatter, Soil science, Error analysis, Data modeling, Statistical analysis, Modeling, Radar, Global Positioning System

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Proceedings Article | 30 November 2006 Paper

Indian Earth Observation Programme toward societal benefits: a GEOSS perspective

Ranganath Navalgund

Proceedings Volume 6407, 640701 (2006) https://doi.org/10.1117/12.697269

KEYWORDS: Satellites, Remote sensing, Sensors, Cameras, Water, Agriculture, Spatial resolution, Microwave radiation, Satellite imaging, Environmental sensing

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SPIE Conference Volume | 5 December 2008

GEOSS, CEOS, and the Future Global Remote Sensing Space System for Societal Benefits

SPIE Conference Volume | 30 November 2006

GEOSS and Next-Generation Sensors and Missions

Conference Committee Involvement (5)

SPIE Asia-Pacific Remote Sensing

11 October 2010 | Incheon, Korea, Republic of

GEOSS, CEOS, and the Future Global Remote Sensing Space System for Societal Benefits

18 November 2008 | Noumea, New Caledonia

GEOSS and Next-Generation Sensors and Missions

13 November 2006 | Goa, India

SPIE Asia-Pacific Remote Sensing

13 November 2006 | Goa, India

Fourth International Asia-Pacific Environmental Remote Sensing Symposium 2004: Remote Sensing of the Atmosphere, Ocean, Environment, and Space

8 November 2004 | Honolulu, United States

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